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Adapting to climate change

Changing climate patterns already affect agriculture in the United States, and the effects will become more pronounced over the next 20 years. To sustain the ability to provide affordable food, feed, fiber and fuel in the future, U.S. agriculture and forestry will need to take a broad, collaborative approach in planning for and adapting to change, according to a new report from the 25x”25 Alliance.

The report, "Agriculture and Forestry in a Changing Climate: Adaptation Recommendations" was compiled by the 25x'25 Adaptation Work Group, a collaboration of agriculture, forestry, business, academic, conservation and government leaders who have spent more than 18 months exploring the impacts of a changing climate and other variables on U.S. agriculture and forestry. The group outlined the report in a web-based news conference on April 2. Panelists for the conference included:

Fred Yoder - Chairman of the Adaptation Work Group and Past President of the National Corn Growers Association

Gene Takle - Iowa State Climate Science Program Director

Chuck Rice - Kansas State University Distinguished Professor of Soil Microbiology, Past-President of the Soil Science Society of America

Ray Gaesser - Iowa Grain Farmer and First Vice President of the American Soybean Association

The 25x’25 Alliance is a broad coalition of groups centered on a goal of U.S. farms, ranches and forests producing 25 percent of U.S. energy needs by 2025, while continuing to meet demands for food, feed and fiber. The group believes U.S. agriculture can achieve that goal, but says climate change will add to the challenges. To address those challenges, 25x’25 assembled a diverse Adaptation Work Group, which produced the recommendations in the report.

During the news conference, Iowa State University professor Eugene Takle, who also serves as director of ISU’s Climate Science program, displayed graphs from the National Oceanographic and Atmospheric Administration and NASA showing a steady increase in atmospheric carbon dioxide since 1960, coinciding with a steady increase in global temperatures.

Takle also showed data from Iowa illustrating the increase in weather extremes. Annual precipitation, on average, has increased in Iowa since 1870, and so have heavy-rainfall years. Since 1950, Iowa has had five years with precipitation averaging over 40 inches. Between 1870 and 1950, there were three such years. There also have been more dry years – seven with precipitation less than 25 inches since 1950 compared with 5 between 1870 and 1950.

Since 1950, Cedar Rapids has experienced 18 years with more than 40 inches of precipitation. Between 1890 and 1950, there were only two such years. In the 1890s, Cedar Rapids averaged 3.6 heavy rain events of 1.25 inches per year. By 2011 the average increased 69 percent to 6.1 days.From 1890 to 1950 there were no years in which daily precipitation exceeded 2.5 inches in eight or more days, but from 1950 through 2010 there were nine such days. Takle points out these heavy rain events create runoff, erosion and loss of topsoil.

ISU projections for future growing season precipitation show a continuing trend toward more high-precipitation years and more low-precipitation years over the coming decades.

These extreme weather events, rather than warming alone, require adaptations such as modified tillage practices to reduce erosion and conserve moisture, and development of more drought-resistant crop varieties.

Takle says climate change has some positive and some negative effects on agriculture. Longer growing seasons can bring higher yields in some commodity crops, and reduced frost damage. Some crops such as fruits in California need chilling hours to ripen. An increase in dry days, particularly in the East, West and South, result in moisture stress on crops. Higher heat and humidity favors more pests and pathogens, and an increase in the number of hot nights reduces livestock performance.

Yoder outlined the adaptation strategies the group recommends, which focus on three actions:

Actions to increase resistance to changes in climate in order to maintain existing practices

Actions to improve resilience by investing in steps that preempt disasters and restore systems in the wake of them

Actions to transform operations

Rice notes there is no single or simple solution for adapting to the changing climate. The group has developed specific recommendations under several broad headings.

Research

Risk Management

Decision-making Tools

Production Systems & Practices

Communications, Outreach, & Education

Carrying out the recommendations will require dialog and collaboration between a range of stakeholder groups. Currently, a variety of groups including Farm Bureau, National Corn Growers Association, Farmers Union, Association of Public Land Grant Universities, National Association of Conservation Districts, Nature Conservancy and others will serve as outreach partners to disseminate and discuss the recommendations.